Process for treating tobacco



Sept 10, 1957 MAX-BARTOLD FREIHERR VON BETHMANN PROCESS FOR TREATING TOBACCO 2 Sheets-Sheet 1 Filed Sept. 9, 1954 [nvenfon- MHK-BARTOLD FREIHERR Vor/ 6ETHmA 6Y Sept 10, 1957 MAX-BARTOLD FREIHERR VON BETHMANN PROCESS FOR TREATING TOBACCO 2 Sheets-Sheet 2 Filed Sept. 9, 1954 INVENTOR.

hm J" 1 MN MN lv United States PatentO rnocass iron TREATING TOBACCO Max-Bartold Freiherr Von Bethmann, Bremen, Germany,

assignor to Martin Brinkmann K. G., Bremen, Germany, a firm Application September 9, 1954, Serial No. 455,041 Claims priority, appiication Germany September 17, 1953 20 Claims. (Cl. 131-140) The present invention relates to a process for treating tobacco and more particularly to a process for de-nicotinizing tobacco in such a way as tov reduce the nicotine content to an insignificant fraction of the nicotine originally present in the tobacco, While retaining all other ingredients and consequently leaving flavor, taste, and aroma substantially unimpaired.

For many years solutions to the problem of denicotinizing tobacco without impairing its flavor, taste, and aroma have been sought and various methods have been proposed. However, up to now it has not been possible to remove the nicotine from tobacco without at the same time unfavorably affecting its flavor.

It is known to render tobacco or a tobacco extract alkaline in order to free the nicotine which then can be driven oh by various methods. This process deleteriously affects the flavor of the tobacco due to chemical reactions occurring when the pH of the tobacco or of tobacco extract is raised above 7 and also because in the process of eliminating the free nicotine, volatile flavoring components are lost.

In order to avoid these disadvantages of the alkaline de-nicotinization methods it has been suggested to extract tobacco with water, alcohol or other solvents. By these treatments, however, not only the nicotine but'also the other ingredients, soluble in the chosen solvent, are removed. This of course also deleteriously affects the quality of the so treated tobacco and consequently these methods too have only found limited application.

Combinations of these two methods have also been tried without leading to useful results.

In another approach to this problem it has been suggested to de-nicotinize tobacco by submersion in water for prolonged periods of time, until the nicotine is destroyed by bacterial action. It was found, however, that bacterial action cannot be limited to the destruction of the nicotine alone, but other extractives of the tobacco, such as sugars, pectins and the like, which are important for the flavor of the tobacco, were also affected.

It appears that the known methods for the de-nicotinization of tobacco have achieved the result of eliminating a considerable part of the nicotine originally present in the tobacco, they have completely failed, however, in providing a de-nicotinized tobacco of satisfactory, original tobacco flavor.

It is an object of the present invention to provide a process for the de-nicotinization of tobacco which overcomes the above mentioned disadvantages of existing methods.

It is a further object of the present invention to provide a process according to which de-nicotinized tobacco can be produced which is substantially the equal in flavor of the original tobacco prior to de-nicotinization, and yet has a nicotine content of less than 20% of its original nicotine content.

It is still another object of the present invention to provide a process for the de-nicotinization of tobacco that canbe exercised with large commercial quantities, resultice water so as to extract the water soluble components of the tobacco including the nicotine and form an aqueous extract solution thereof, separating the aqueous extract solution containing the nicotine from the thus extracted tobacco, subjecting the thus separated extract solution to ion exchange with an ion exchanger adapter to remove the nicotine from the extract solution, thereby obtaining a de-nicotinized extract sOlutiOn, mixing the de-nicotinized extract solution with the extracted tobacco so as to form a Water-tobacco mixture including the water soluble com-' ponents of the original tobacco except for the nicotine, and drying the water-tobacco mixture so as to obtain a de-nicotinized tobacco containing substantially all of the original water soluble .components thereof except for the nicotine. 7

It has been found that tobacco de-nicotinized by the process of the present invention contains practically all extractives and in the same amount present in the uritreated tobacco with the exception of the nicotine. Thus treated tobacco therefore completely retains its original desirable flavor.

Best results are obtained with the process of the present invention by executing the Water extraction in consecutive steps whereby in each step the weight relationship between the tobacco and the extract solution serving as solvent is adjusted to a predetermined proportion preferably of between 8 and 12 units by weight of solvent to 1 unit by weight of tobacco and most preferably 10 units of water per each unit of tobacco.

After the tobacco has been substantially completely extracted it is then treated with concentrated de-nicotinized extract solution coming from the ion exchanger. This extract solution contains practically all the soluble ingredients previously extracted from the tobacco with the exception of the nicotine. ture of extracted tobacco and de-nicotinized extract solution, and by properly adjusting the concentration of the extract solution and the quantity of extract solution to be dried with reference to the amount of extracted tobacco, it is possible to obtain, if desired, a reconstituted de-nico:

tinized tobacco containing all extractives, except for the nicotine, in substantially the same proportions in which they were present prior to the treatment of the original tobacco.

It has been found advantageous to mix together extracted tobacco and a de-nicotinized tobacco extract solution containing a percentage of extractives equal to the percentage of extractives that were originally present in the untreated tobacco, except for the nicotine. In such event it is possible to finally dry extracted tobacco mixed with an equal weight of extract solution so thatthe finally dried tobacco contains the same percentage concentration of extractives, except for nicotine, as the original untreated tobacco. it has been found that the drying of tobacco with an equal weight of extract solution permits the best drying without the necessity of using heat to a greater extent than in the customary drying of tobacco and without any possibility of dripping off of the solution which would affect the concentration of extractives in the final dried tobacco. This is most advantageously achieved the tobacco extraction and the ion exchanger until the concentration of extractives in the extracting solution By drying together a mix- This is advantageous in that.

reaches an equilibrium-with. the. concentration of extractives in the original tobacco.

To the extent that the ion exchanger retains metal ions from the tobacco extract solution and possibly changes the pH. of the solution, the original pH and content. of metal. salts can be restored in the de-nicotinized solution by cycling the solution. through a tower filled with for example magnesium carbonate. or dolomite. As will be shown. below, only. part of the de nicotinized tobacco extract solution. leavingthe ion exchanger is used for mixing with extracted. tobacco in order to reconstitute. in. the tobacco the previously extracted. ingredients except. for the nicotine. Another portion, and frequently the larger portion. of the; de-nicotinizedextract. solution. leaving. the ion exchanger; is used .as solvent for the extraction. of the tobacco. and. thereafter is pumped again through theionexchanger; a

In order notto. unnecessarilyovcrload the. ion exchanger and also to reduce the amount of magnesium carbonate used, only that portion of. the. de-nicotinized tobaccotexa tract solution leaving the." ion; exchanger. which .is tube. used for mixingrwithrthe extracted tobacco, willTbecycled through the magnesium carbonate towen t.

- The preferred pH. value tobe .obtained by. cycling: of the de-nicotinizedtobacco. extract; solution through. the: magnesium carbonate tower is within the range .of. pH-

4.0. to 5.5., Itis important to note; that during the whole processan increase of thepHinto thealkaline range,

with its harmful consequences, is avoided.

.The mixture, of. extracted tobacco and de-nicotinized, pH-adjusted tobacco extract solutiontrnaythenlbe dried by any of the conventional methods, preferably without the use of substantiallyelevated temperatures and thus without danger ofundesirable chemical reactions or loss of volatile ingredients. I

In apreferred embodiment of the process of the present invention tobacco isextracted with water in three. consecutive steps, usingfor the extraction of. onepart by weight" of tobacco,.ten.parts by weight of water and proceeding with the ext'ractionin each step. for one hour at room temperature. After. completion: of each step nine parts of the. solution: are ,squeezedout, leaving one part in the tobacco; Upon. repeatingthe extraction step three,times, whileqmovingtt-obacco. and water solution in.

countereurrent direction from. step to steps. substantially all-of the nicotine withtheexceptiomofa fraction of 1% is removed frornthe tobacco; I L

This countercurrent, stepwise-extraction ,process-may dv n us h e ec t n ydb. W e Y t e centrated extractsolution.afterbeing used inathree consecutive: extractiodsteps is. de-nic otinizedin the: ion. ex-

changer and thereafterreintroducedinthecycle-by beingrxused. for thetfinal extraction. oftobacco whichzhas previously already been extracted in two successive steps. At this final extraction step of the tobacco freshwater. is .added, ,together. with the .de nicotinized tobacco extract solution coming, from theion: exchanger, in the amount required toreplace the water. which-leaves the process with the reconstituted de-nicotinized tobacco and extract mixture.; y I

1 By following the above procedure; de-nicotinized tobaccoof .very highqualitycan be produced, since substantially all .ing'redi ents except for. the nicotine are'retained. Furthermore, .only. arelativ ely small amount of water, approximately equalto the weight; of the dry tobacco, has. to. be. removed and this drying-process. canv easily. be arranged at. the; conventional, tobacco drying temperature andwithout.appreciable loss of volatile ingredients, or heat-induced chemical reactions In addition,.the concentrated extracts obtained-by this process. show excellent resistance against fermentation and spoil-.-

age. The process of. the present invention may also'xbeutilized in the productionnof de-nicotinized tobacco' extracts' from tobacco waste and dust. About 30 to 40% water solubles may be extracted from tobacco waste products and de-nicotinized as outlined above. The resulting denicotinized tobacco extract solutions may be used to improve the quality and increase the strength of tobaccos which may or may not have been previously de-nicotinized.

The novel features which are considered as character istic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing, in which:

Fig. 1 is a diagrammaic view of an installation for the performance of the process of the present invention; and

Fig. 2 is a schematic illustration of the various manners in which three ion exchangers can be operated in accordance with the present invention.

Referring now to the drawing and particularly to Fig? 1, it'ca'ti be seen that the untreated tobacco enters ta'nk'Z by meansof'a suitable conventional feeding arrangement 1. In tank 2 the tobacco is extracted with a tobacco extract solution coming from tank 5. After being extracted for about one hour at room temperature, the tobacco is moved by means of conveyor 3 through a setof rollers 4 into tank' 5. In one of the processes included-within th'e'present invention, the tobacco is treated in tank 2 with ltltimes its weight of tobacco extract sotion. By being squeezed through the set of rollers 4, a part of the extract solution adhering to the tobacco is forced back into tank 2. The set of rollers dmay be so adjusted that tobacco containing an amount of extract solution equal to its own dry weight is dumped into tank 5. t

In tank 5' a' second extraction of the tobacco with for instance 10 times its own weight of extract tobacco solution takes place, the tobacco extract solution coming from tank 8. After about an hour of extraction, the.

tobacco is moved by means of conveyor 6 through a set of rollers 7 into tank 8. Again the sctof rollers may be adjusted in such a way that the tobacco reaching tank 8 willcontain' extract solution in an amount equal to its own dry weight. a

In tank 8, a third and final extraction of' the tobacco takes place. .The' extract solution used in this extraction enters tank 8 through conduit 18. The amount of extract solution available through conduit 18 will not quite sufficc, therefore. Water is. added through faucet 11 in an amount suificient tomake up the difference.

.The' tobacco extract'solution used for'the extraction of fresh tobacco intank 2, 1eaves tankz through conduit 13 and is pumped by meanslof pump 14 through filter 15 (for the-removal of solidimpurities). into ion exchanger'16. In ionexchanger 16. the nicotine and some of the metal ions are removedfromthe. extract solution which is then pushed through conduit" 17 into conduits 18 and 20. The part of the de-nicotinized extract solution permitted to flow through conduit 18 enters tank 8 and isthere used for the final extraction of the tobacco as outlined above.

The tobacco leaving tank 8 by means of conveyor 9 is squeezed through a set of rollers 10 so as to contain an amount of extract solution equal to its own weight, and falls into tank 19.. The tobacco received in tank 19 is already sufficiently freedof nicotine. Since not only the nicotine but also other soluble ingredients have been ex tracted, it is now necessary to reconstitute these other soluble ingredients in order to restore the tobacco to its original flavor.,

For this purpose. de-nicotinized tobacco extract solution coming from ion exchanger 16 by way of conduits 17 de-nicotinized tobacco extract. solution in tank 19, the

magnesium carbonate containing column or tower 23, and finally through conduit 24 back into tank 19. The speed of flow is so arranged as to permit the solution, while passing through the magnesium carbonate tower 23, to pick up the metal salts in a percentage amount equal to the percentage of metal salts contained in the original tobacco.

In the execution of the process here discussed, it is desirable to have the concentration of all tobacco solubles, except nicotine, in the extract solution in tank 19 reach a percentage. equal to the percentage of these solubles in the original untreated tobacco which has been extracted therefrom.

' The extracted-tobacco coming from the set of rollers is mixed in tank 19 with the above described nicotinefree tobacco extract solution and removed from tank 19 by way of conveyor 25 and rolls 26. Rolls 26 are so adjusted as to squeeze out of the tobacco all extract solution in excess of an amount equal to the dry weight of the tobacco.

The moist tobacco coming from set of rollers 26 is than air or otherwise dried by known methods so as to prevent volatilization of flavoring components. The dried tobacco will then contain all soluble ingredients except nicotine in the same proportions in which they were present in the original untreated tobacco.

The cation exchanger 16 may be arranged as an hydrogen ion exchanger or as a metal ion exchanger, preferably a potassium ion exchanger.

The advantage of the potassium ion exchanger lies in the fact the pH value of the de-nicotinized extract solution remains practically unchanged. However, the capacity of the potassium ion exchanger is somewhat smaller, furthermore, it is necessary to regenerate the exchanger first with hydrochloric acid and then to transform it into a potassium exchanger with the help of potassium chloride solution. This is necessary because a cation exchanger after being saturated with nicotine can only be quantitatively regenerated by Way of the hydrogen ion exchange arrangement.

The extract solutions leaving a cation exchanger in its hydrogen ion form are, especially at the beginning of the operation, rather far on the acid side. The advantage of this is that the solutions remain stable at a pH below 3 and it is then not necessary to arrange for additional precautions in order to prevent fermentation during the treatment of the extracts. Working in this way, however, practically all metal salt ions are taken out of the solution. Consequent disadvantages can be eliminated by treating the extracts with suitable salts after they have left the exchanger column. Preferably the original pH value 'of between 4.0 and 5.5 can be readjusted by piping the extract over magnesium carbonate or dolomite.

In order to prevent an unnecessary load on the exchanger columns and in order not to use up too large quantities of salts like magnesium carbonate, it is desirable to adjust the pH of only the part or" the de-nicotinzed extract solution which will remain in the treated tobacco and not to adjust the pH of the part of the extract solution which will be used in countercurrent for the de-nicotinization of additional quantities of tobacco.

The execution of the tobacco extraction process may be so controlled that the relation between tobacco and water throughout the whole system is maintained as 1:10, whereby the tobacco remains for about one hour in the individual extraction steps and contains upon leaving the system, with the exception of the nicotine, all the extractives that were removed in the preceding operations. The sets of rolls are then preferably so adjusted that of'the solution from the preceding process step are kept back.

Such treated tobacco contains practically 100% of its original extractives, exclusive of nicotine and similar solution is cycled through conduit 21, pump 22, and the' amino-compounds.

are advantageously and customarily added to the tobacco, such as cane sugar, invert sugar or glucose, sorbitol, glycerol, glycols, aromatic fruit extracts, also glow promoting substances such as saltpeter, and the like.

The tobacco coming from the last set of rolls may be dried in conventional ways to the usual moisture content required for the cutting of the tobacco. It has proven especially advantageous to remove the surplus water under reduced pressure. It is also possible to accomplish the final drying to the usual moisture content in known ways by roasting the cut tobacco.

It is advantageous to use in the execution of the process of the present invention several, for instance 3, connected ion exchanger columns of suitable size in series. Hereby the first column is first charged to capacity, while it is the purpose of the second and third columns to exchange the quantities of nicotine which after some time start to pass through column 1. Later on, one proceeds in such,

a way that as soon as nicotine passes through the second column, the third column is connected and the first column disconnected for regeneration. When nicotine starts to pass through the second column, the regenerated first column is added to the series and the second column is cut on for regeneration, and so on.

As schematically shown in Fig. 2, the three ion exchanger columns 1, 2 and 3 can be operated in various ways so that always two columns operate in sequence while one column is regenerated.

The three columns can be operated according to three different schedules.

According to schedule 1, column 1, and 2 operate in sequence and column 3 is regenerated.

According to schedule 2, columns 2 and 3 operate in sequence and column 1 is regenerated.

According to schedule 3, columns 3 and I operate in sequence and column 2 is regenerated.

When operating according to schedule 1, valves 1, 2, 3, 4, 5 and 6 are open and valves 7, 8, 9, 10, 11, 12, 13 and 14 are closed. The extract solution which is to be denicotinized enters through valve 1 and leaves the ion exchange system through conduit 30. During operationof the apparatus, small quantities of the liquid may be drawn off at valve 15 for testing whether nicotine is present in the liquid leaving the ion exchangers, thus indicating that column 1 has beensaturated and should be replaced by column 3. A suitable precipitation reaction, for instance with silicotungstic acid may-beeemployed for this test. When regenerating column 3, valves 19, 24 and 25 are open, and valves 20, 21, 23, 26, 27 and 28 are closed. The regenerating solution enters through valve 19 and is released after completion of the regeneration process.

through valve 28. Prior to releasing the regeneration solution it is necessary to check that the regeneration solution leaving through conduit 29 is substantially free of nicotine.

After the regeneration of column 3 has been completed and the regeneration solution remaining in column 3 has.

been released through valve 28,.valve 19 is closed. and column 3 is flushed by means of valve 18 while valves 28, 27 and 26 are closed. Thewash water remaining in column 3 is then also released through valve 28.

In the customary manner (not illustrated) care is taken that the regenerating solution and the water used for flushing the column do not mix.

When operating according to schedule 2, valves 1, 2, 8, 5, 11, 12 and 14 are open and valves 7, 3, 9, 4, 10, 6 and 13 are closed. In this case liquid for the nicotine test is withdrawn at valve 16.

For regenerating column 1, valves 19, 20 and 21 are open and valves 22, 24, 23, 25, 26, 27 and 28 are closed. In this case after closing of valve 19, column 1 is emptied through valve 26 and is flushed by opening valve 18 while If desired, it is also possible to add. to the extract solution in tank'19 other ingredients which,

a es 26), .17 and a s Th urplus w ter is then againwithdr'awn through valve 26.

Whenoperating according to schedule 3, valves 1, 7, 13; 10, 8; Sand 9 are open, and valves 2, 4, 5, 6, 111, 12 and I4 are closed; Liquid for; the nicotine test is withdrawn at valve 17.

For regenerating columnZ, valves 19, Hand 23 are open and valves 20, 21', 24, 25, 26, 27 and 28are closed; Column 2 is emptied through valve ZI'after valve 19 has of alcoholic; hydrochloric acid at'r'aised temperatures of about 40 to'SO' degrees, centigrade. In consideration of the life span ofthe' exchanger, temperatures in excess of 50 degreessbould, if 'possible,.be avoided.

It isadvantageou's to use the hydrochloric acid for regeneration in a cycle by dividing the total amount into about three to four equalparts...

At the beginning the hydrochloric acid passing through a spention exchanger takes up large quantities. of nicotine. After a short time, the concentration of nicotine in the regenerating liquididrops considerably and then slowly diminishes further towards the zero value.

In order to save recovery and distillation costs, only the first thi'rd or quarter of the regenerating liquid, containing the major portion of the nicotine, is reactivated. The following portions, containing only small amounts of nicotine are used without reactivation for the regeneration ofsuccessive spent ioii exchanger, and finally, new, or adjusted reactivated regenerating liquid is again introduced.

The first and most saturated-portion of the spent regenerating liquidis preferably reworked by distilling off the alcohol andthe hydrochloric acid, whereupon the distillation residue contains all the nicotine as chlorohydrate, and also any other ingredients removed from the tobacco. This residue is treated in known ways for the recovery of nicotine. p V

The nicotine free' alcoholic hydrochloric acid obtained through distillation of theregenerating liquid may be reused upon adjustment of:its;original composition by ad- I dition, if necessary, f alcohol and hydrochloric acid.

. The possibility of obtaining nicotine concurrently with the. de-nicotiniiation of the tobacco constitutes a further r important advantage of the process in accordance with the present invention, since aconsiderable part of the operating costs of the process of the present invention may be recovered by the sale ofnicotine.

Tl'1e process of the present invention may also be used for the recovery of soluble ingredients from tobacco wastes under simultaneous separation of the nicotine from the other extractives. This is of considerable economic importance and was not possible until the present process permitted the de-nicotinization of tobaccoextracts with the retention of all extractives except for the nicotine.

While it is possible to adjust the metal ion content and pH of these extracts from tobacco wastes to their original values by cycling these extracts through the magnesium carbonate column 23, it has-provenespecially advantage:

ous to use these extractsfrorn tobacco wastes at the pH i successive steps of the process in the apparatus shown in" the drawing. Description of the simultaneously executed processing of other batches of tobacco in different stages of the process of the present invention has beenomitted for'the sake of clarity.

EXAMPLES I pounds of tobacco of the above composition are steeped in tank 2 for one hour in 950 pounds of aqueous tobacco extract coming from tank 5.

During this steeping process 12 pounds of tobacco extractives are dissolved in the aqueous-extract solution.

After completion of this first one hour steeping process, the wet tobacco is squeezed through the set of rollers 4. The moist tobacco leaving rollers 4 is dumped into tank 5 and the watery-extract solution which remained in tank 2 is pumped through a filter 15 into the zeolite potassium After completion of this second one hour steeping process, 200 pounds of moist tobacco are dumped into tank 8 via the set of rollers 7 and 950 pounds of waterytobacco extract solution flow into tank 2 to be used in the first one hoursteeping process described under I.

The 200 pounds of moist tobacco dumped into tank 8 have a composition of 80 pounds tobacco containing 13 pounds of extractives (8 pounds of extractives having been extracted during the second steeping process) and pounds of extract solution.

The 200 pounds of moist tobacco received from tank 5 are steeped for one hour in tank 8 with 900 pounds of extract solution coming mostly from conduit 18 and to the extent that conduit '18 does not furnish a suflicient quantity, fresh water to make up the 900 pounds isadded from faucet 11.

After completion of this third one hour steeping process, pounds of moist tobacco are dumped into tank 19 via the set of rollers 10 and 950 pounds of waterytobacco extract solution flow intotank 5 to be used in thesecond one hour steeping process described under 11.

The 150 poundsof moist tobacco dumped into tank 19 have a composition of 67 pounds of insoluble tobaccoconstituents and 7 pounds of soluble compounds including a small fraction of the nicotine, and 76 pounds of extract solution.

The .850 pounds of concentrated extract solution referred to under I are pumped into the ion exchanger 16,.

are freed of their nicotine content while passing through the ion' exchanger, and are led into conduit 17 which branches into conduits 18 and 20.

The extract leaving the ion exchanger contains all of the water soluble extractives removed from the tobacco during the three one hour steeping processes, with the exception of the nicotine and some metal ions like magnesium', which'were also retained in the ion exchanger.

Part of-the1extract leaving the ion exchanger flows through conduit 1718 into tank 8 where together with fresh water added from faucet 11 it makes up the 900 pounds of extractsolution used. in the third steeping process as described under III.

-..The 74 pounds of tobacco dry substance received in tank 19 from rollers 10 contain only a small fraction of the original nicotine content (about 0.4 pound), and the extractives contained in the 76 pounds of solution accompanying the 74 pounds of dry substance are practically free of nicotine originating from the tobacco extractives dissolved in the third steeping process.

In this third steeping process (in tank 8), 6 pounds of the extractives contained in the original tobacco are dissolved. The total amount of nicotine dissolved in this step weighs about 0.6 pound. This 0.6 pound of nicotine is dissolved in 950 pounds-of extract solution and only 76 pounds of this solution, or less than 10% reach tank 19. Consequently the total amount of nicotine reaching tank 19 amounts to less than 0.05 pound. As will be shown below, the 74 pounds of tobacco dry substance are reconstituted with nicotine-free extracts to about 97 pounds. The so reconstituted tobacco contains less than 0.45 pound nicotine in 100 pounds of untreated tobacco. In other words the nicotine content which has been 3 in the untreated tobacco is thus reduced to about 0.45%.

900 pounds of de-nicotinized extract coming from the exchanger '16 are added by way of conduits 1720 to the 150 pounds of moist tobacco received in tank 19. The de-nicotinized extract solution in tank 19 is recycled through conduit 21, pump 22, magnesium carbonate column 23, and conduit 24 back to tank 19. It is the purpose of this recycling to restore to the de-nicotinized extract solution the metal-ions which have been retained in the ion exchanger 16, in the form of magnesium-ions. The flow ofthis recycling process is adjusted so as to permit the metal-icns content of the solution to regain the value it had prior to entering the ion exchanger. (For subsequent batches only small amounts .of extract have to be added in order to keep tank 19 properly filled.)

VII

It will be understood that while in the present example the process of the invention is described by following one 100 pound batch of tobacco through the variousprocess steps, actually all steps take place simultaneously with,

successive batches of tobacco. The recycling of the extract solution from tank 8 to tank to tank 2 through the ion exchanger 16 and back to tank 8, with the addition of only sufficient water to make up for the amount of extract solution which is taken out of the cycle through conduit 20, permits a gradual increase in the extract concentration in the solution to about 20-30%. Once this concentration has been obtained, the thus-formed equilibrium is kept constant as long as the process continues. A concentration of 20-30% extracts in the solution is necessary to successfully complete the final step described below. Suitable arrangements have to be made during the treatment of the first few batches upon starting the process, by either adding sufficiently concentrated extract solution obtained in a previous'operation, or by putting aside the first few batches of tobacco until the extract solution has been concentrated and later re-introducing these first few batches in small quantities together with fresh tobacco.

VIII

In the final step of the process, de-nicotinized extractsare added to the extract-free tobacco in tank 19, in sufficient quantities to reconstitute a tobacco containing all of its original extractives, except for the nicotine.

The tobacco-concentrated extract suspension from tank 19 is squeezed through rollers 26. These rollers areso adjusted as to permit the 74 pounds of tobacco to retain; 100 pounds of extract solution. Upon subsequent drying of this moist tobacco, the water contained in the extract solution is I removed at normal temperatures so .as to pre vent any chemical changes in the extractives which are. now retained in the tobacco.

One obtains from 74 pounds of tobacco dry substance While the invention has been illustrated and described.v

as embodied in a three step extraction process, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention, i. e. by increasing the number of extracting steps and/ or further diminishing the nicotine content of the tobacco.

Without further analysis, the foregoing will so fullyreveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A process of extracting nicotine from tobacco, comprising the steps of treating a predetermined quantity of tobacco with a first amount of water equal to between eight and twelve times the weight of said tobacco so as to extract the water soluble components of said tobacco including the nicotine and metal ions, and form an aqueous extract solution thereof; separating a major predetermined portion of said aqueous extract solution from said tobacco; adding to the thus remaining tobacco an amount of water equal to said first amount of water; separating a portion of the thus formed aqueous extract solution equal to said major predetermined portion thereof; re-

peating said treating and separating steps with fresh water a predetermined number of times; subjecting said separated extract solutions to ion exchange at a pH not higher than 7.0 with an ion exchanger adapted to'remove the nicotine from said extract solutions, thereby obtaining de-nicotinized extract solutions; mixing said de-nicotinized extract solutions with said extracted tobacco so as.

to form a water-tobacco mixture including the extracted water soluble components of the original tobacco except for the nicotine; and drying said water-tobacco mixture so as to obtain a de-nicotinized tobacco containing substantially all 'of the original watersoluble components thereof except for the nicotine and a portion of the metal having metal ions removed therefrom; replacing said re-;

moved metal ions in said de-nicotinized extract solution so as to form a regenerated de-nicotinized extract solution including substantially all of the extracted water soluble components of the original tobacco except for the nicotine; mixing said regenerated de-nicotinized extract" solution with said extracted tobacco so as to form a water-tobacco mixture including the extracted water soluble components of the original tobacco except for the.

lot he original} W er s l co n pt to hsn' c n' -l t A Proc s fisx ra tins ni ot n f om tobacco omprising the" steps oftrefating tobacco withwa'ter so as to extractthewater soluble components of said tobacco including the nicotine and form an aqueous extract solution thereof; separating said aqueous extract'solution containing said nicotine from the thus extracted tobacco; subjeeting the thus separated extract solution to ion exchange w th an i 9 nssr1 fl t t d o ih i in's from saidextract solutionj thereby de-nicotinizing and simultaneously removing metal ions from saidjextract solution and forming a' de-nicotin'ized extract solution having metal ions removed therefrom; ,mixing said donicoti nized extract solution having said metal ions removed therefrom with said extracted tobacco while adding to the thirsQfdrrned water tobacc'o mixture metal ions of'the amount tore'place said: removed metal ions so as t'oyform a water-tobacco mixture including substantially all of the extracted water soluble components of the original tobacco except for the nicotine; and drying said wafer-tobacco mixture sofas to obtain a de-nicotinized tobacco containing substantially all of the original water soluble components thereof except for the nicotine.

4. A process of extractingnico'tin'e from tobacco, comprisin'g the steps of treating-tobacco with a predetermined portion of water so as to extract the water soluble components of said tobacco including the nicotine and form an aqueous extract solution thereof; separating a major predetermined portion of said aqueous extract solution from said tobacco; adding to the thus remaining tobacco a portion-of water equal to" said predeterminedportion of water; separating a portion of the thus formed aqueous extract solution equal to said major predetermined portion thereof; repeating said treating and separating steps apredetermined number of times; subjecting said sepa- 12 win s-n c nailed: tobacco 0 rated eXtract solutions to ion exchange with an ion ex-" changer adapted to remove the nicotine from said extractsohitions'; thereby de-nicotinizing and simultaneous- 1y removing metal ions from said extract solutions and forming de- 'nicotinized extract solutions having metal ions removed therefrom; replacing said removed metal ions in said de-nicotiniz'edlextr act-solutions so as to form regenerated de-nicotinized extract solutions including substantially all of the extracted watersoluble components of the original tobacco except 'for the nicotine; mixing saidrege'ncrated de-nic'otinized extract solutions with said extracted tobacco so as to form a water-tobacco mixture including the extracted water, soluble components of the originaltobacco except for the nicotine; and drying said water-tobacco mixture so as to obtain a denic'otinizedtobacco containing substantially all=ofthe original water soluble components thereof except for the nicotine.

5. A process of extracting nicotine from tobacco, comprising the steps of treating tobacco with a predetermined portion of Water so as to extract the water soluble components of said tobacco including the nicotine and form an aqueous extract solution thereof; separating a major predetermined portion of said aqueous extract solution from said tobacco; adding to the thus remaining tobacco a portion of water equal to said predetermined portion of water; separating a portion of the thus formed aqueous extract solution equal to said major predetermined portion thereof; repeating said treating and separating steps a predetermined number of times; subjecting said separated extract solutions to ion exchange with an ion ex changer adapted to remove the nicotine from said extract solutions, thereby de-nicotinizing and simultaneously removing metal ions from said extract solutions and forming de-nicotinized extract solutions having metal ions removed therefrorn;'mixing said de-nic'otinized extract solutions having said metal ions removed therefrom with said extracted tobacco While adding to the thus formed watersass-sac tobacco mixture metal ions of the amountto replace said removed metal ions so as to form a water-tobacco mixture including substantially all of extracted water soluble components of the original tobacco except for the nicotine; and drying said water-tobacco mixture so as to obtain a de-nicotinized tobacco containing substantially all of the original water soluble components thereof except for the nicotine.

6. A process of extracting nicotine from tobacco, comprising the steps of treating a first batch of tobacco with a predetermined amountof water so as to extract the wate r soluble components of said tobacco including the nicotins and metal ions, and form an aqueous extract solution thereof; separating said aqueous extract solution from said first batch of tobacco; treating a predetermined number of additional batches of tobacco with said separated aqueous extract solution, separating the formed aqueous extract solution from each additional treated batch of tobacco before treating the next batch of tobacco therewith; subjecting the extract solution separated from the last batch of treated tobacco to ion exchange at a pH ot h h r than 7-.0 wi h n i n xch nger p ed to remove the nicotine from said extract solution, thereby obtaining a de-nicotinized extract solution; mixing an amount of said de-nicotinized extract solution with a batch of extracted tobacco in an amount such that the thus formed water-tobacco mixture contains substantially all of the extra'cted' water soluble components of the original batch of tobacco in the amount originally cont'a'in'edtherein except for the nicotine; and drying said water-tobacco mixture so as to obtain a substantially de-nicotini'zed tobacco containing substantially all of the original water soluble components thereof except for the nicotin'eand a portion of the metal ions.

'7. A process of extracting nicotine from tobacco, comprising the steps of treating a predetermined amount of tobacco'with a predetermined amount of water so as to extract the water soluble components of said tobacco including the" nicotine and metal ions, and form an aqueous extract solution thereof, the treating being continued at a temperature below 50 C. until the concentration of extractives in the solution reaches an equilibriuni value; separating said aqueous extract solution containrng said nicotine from the thus extracted tobacco; subjecting the thus separated extract solution to ion exchange at a pH not higher, than 7.0 with anion exchanger adapted to remove the nicotine from said extract solution, thereby obtaining a de-nicotinized extract solution; a predetermined amount of the extracted tobacco with an equal amount of said de-nicotinized extract solution so that the formed mixture contains substantially all of the extracted water soluble components of the original tobacco. in the amount originally contained therein except for; the nicotine; and drying said watertobacco. Qniiittlure so. as; to obtain a substantially de-nicotbbaceocontaining substantially all of the original water soluhlecomponents thereof except for the nicotine and a] portion of the metal; ions. V

8;. A: process of extracting; nicotine from tobawo,l 60mpi'ising the st eps oftreating several batches of tobacco each with several predetermined portions of water in countercurr ent, equalpredetermined amounts of the formed extract solutions being separated from: each treated batch of tobacco before the next batch of tobacco is treated with the separated equal portion of said extract solution-,the formed extract solutions containing the water soluble components or said tobacco including. the nicotine and metal ions; continuing the counter-L current treatmentby recycling the; extract solution from the last batch of tobacco to be treated to the first batch of" tobacco until an equilibrium between the concentration of extractives in the solution and the tobacco is solution, thereby obtaining a denicotinized extract solution; mixing a predetermined amount of the extracted tobacco with an equal amount of said denicotinized extract solution so that the formed mixture contains substantially all of the extracted water soluble components of the original tobacco in the amount originally contained therein except for the nicotine; and drying said Water-tobacco mixture so as to obtain a substantially denicotinized tobacco containing substantially all of the original water soluble components thereof except for the nicotine and a portion of the metal ions.

9. A process according to claim 8 in which said portions of water are between 8-12 times the weight of said batches of tobacco.

10. A process according to claim 8 in which said portions of water are about 10 times the weight of said batches of tobacco and wherein about 90% of the formed extra ct solution is separated from each treated batch of tobacco before treatment of the next batch of tobacco therewith.

11. A process of extracting nicotine from tobacco, comprising the steps of treating several batches of tobacco each with several predetermined portions-of water in countercurrent, equal predetermined amounts of the formed extract solutions being separated from each treated batch of tobacco before the next batch of tobacco is treated with the separated equal portion of said extract solution, the formed extract solutions containing the water soluble components of said tobacco including the nicotine; continuing the countercurrent treatment by recycling the extract solution from the last batch of tobacco to be treated to the first batch of tobacco until an equilibrium between the concentration of extractives in the solution and the tobacco is attained; subjecting said formed extract solution to ion exchange with an ion exchanger adapted to remove the nicotine from said ex tract solution, thereby de-nicotinizing and simultaneously removing metal ions from said extract solution and forming a de-nicotinized extract solution having metal ions removed therefrom; replacing said removal metal ions in said de-nicotinized extract solution so as to form a regenerated de-nicotinized extract solution including substantally all of the extracted water soluble components of the original tobacco except for the nicotine; mixing a predetermined amount of the extracted tobacco with an equal amount of said regenerated de-nicotinized extract solution so that the formed mixture contains substantially all of the extracted water soluble components of the original tobacco in the amount originally contained therein except for the nicotine; and drying said watertobacco mixture so as to obtain a substantially de-nicotinized tobacco containing substantially all of the original Water soluble components thereof except for the nicotine.

12. A process according to claim 11 in which said removed metal ions are replaced during the mixing of said extracted tobacco with said de-nicotinized extract solution.

13. A process of extracting nicotine from tobacco, comprising the steps of treating several batches of tobacco each with several predetermined portions of water in countercurrent, equal predetermined amounts of the formed extract solutions being separated from each treated batch of tobacco before the next batch of tobacco is treated with the separated equal portion of said extract solution, the formed extract solutions containing the water soluble components of said tobacco including the nicotine and metal ions; continuing the countercurrent treatment by subjecting the extract solution from the last batch of tobacco to be treated to ion exchange with an ion exchanger adapted to remove the nicotine from said extract solution and recycling said de-nicotinized extract solution to the first batch of tobacco until an equilibrium between the concentration of extractives in the solution and the tobacco is attained; subjecting said formed extract solution-to ion exchange at a pH not higher than 7.0'with an ion exchanger adapted to remove the nicotine from said extract solution, thereby obtaining a de-nicotinized extract solution; mixing a predetermined amount of the extracted tobacco with an equal amount or said de-nicotinized extract solution so that the formed mixture contains substantially all of the extracted water soluble components of the original tobacco in the amount originally contained therein except for the nicotine; and drying said water-tobacco mixture so as to obtain a substantially de-nicotinized tobacco containing substantially all of the original water soluble components thereof except for the nicotine and a portion of the metal ions.

14. A process of extracting nicotine from tobacco, comprising the steps of treating several batches of tobacco each with several predetermined portions of water in countercurrent, equal predetermined amounts of the formed extract solutions being separated from each treated batch of tobacco before the next batch of tobacco is treated with the separated equal portion of said extract solution, the formed extract solutions containing the water soluble components of said tobacco including the nicotine; continuing the countercurrent treatment by recycling the extract solution from the last batch of tobacco to be treated to the first batch of tobacco until an equilibrium between the concentration of extractives in the solution and the tobacco is attained; subjecting said formed extract solution to ion exchange with an ion exchanger adapted to remove the nicotine from said extract solution, thereby obtaining a de-nicotinized extract solution; re-

- placing in a predetermined amount of said concentrated de-nicotinized extract solution the metal ions removed during de-nicotinization of that extract solution, in an amountsuch that the concentration is in conformity to the concentration of metal ions present in the untreated tobacco; mixing said concentrated de-nic'otinized, metal ions-containing extract solution with an equal amount of extracted tobacco so that the formed mixture contains substantially all of the extracted water soluble components of the original tobacco in the amount originally contained therein except for the nicotine; and drying said watertobacco mixture so as to obtain a substantially d e-nicotinized tobacco containing substantially all of the original water soluble components thereof except for the nicotine,

15. A process of extracting nicotine from tobacco, comprising the steps of treating several batches of tobacco each with several predetermined portions of water in countcrcurrent, equal predetermined amounts of the formed extract soiutions being separated from each treated batch of tobacco before the next batch of tobacco is treated with the separated equal portion of said extract solution, the formed extract solutions containing the water soluble components of said tobacco including the nicotine; continuing the countercurrent treatment by recycling the extract solution from the last batch of tobacco to be treated to the first batch of tobacco until an equilibrium between the concentration of extractives in the solution and the tobacco is attained; subjecting said formed extract solution to ion exchange with an ion exchanger adapted to remove the nicotine from said extract solution, thereby obtaining a de-nicotinized extract solution; replacing in a predetermined amount of said concentrated de-nicotinized extract solution the metal ions removed during de-nicotinization of that extract solution, in such amount as to obtain in said predetermined amount of said concentrated de-nicotinized extract solution a pH value substantially equal to the pH value of said formed extract solution prior to its being subjected to ion exchange; mixing said concentrated de-nicotinized, metal ions-containing extract solution with an equal amount of extracted tobacco so that the formed mixture contains substantially all of the extracted water soluble components of the original tobacco in the amount originally contained therein except for the nicotine; and

drying; said water-tobacco -mixture so asto obtain a-substanti'ally d e-nicotinized tobaccofcontaining substantially all of the originahwater soluble components thereof ex cept for the nicotine. v p 1 16. A process of extracting nicotine frorn't'obacco, comprising the, steps of treating several batches of tobacco each with several predetermined portions of water in countercurrent, equal predetermined amounts of the formed extract solutions being separated from each treated batch of tobacco before the next batch of tobacco is treated with the separated equal portion of said extract solution, the formed extract solutions containing the water soluble comp onents ofi said tobacco including the nicotine; continuing the countercurrent treatment by recycling the extract solution from the last batch of tobacco to be treated to the first batch of tobacco until an equilibrium between the concentration of extractives in the solution and the tobacco is attained; subjecting said formed extract solution to ion exchange with an ion exchanger adapted to remove the nicotine from said extract solution, thereby obtaining a de-nicotinized extract solulion; replacing in a predetermined amount of said concentrated de-nicotinized extract solution the metal ions removed during de-nicotinization of that extract solution,

in such amount as to obtain in said predetermined amount of said concentrated de-nicotinized extract solution a pH value between 4.0 and 5.5; mixing said concentrated denicotinized, metal ions-containingextract solution with an equal amount of extracted tobacco so that the formed mixture contains substantially all of the extracted water soluble components of the original tobacco in the amount originally contained therein except for the nicotine; and drying said water'tobacco mixture so as to obtain a substantially de-nicotinized tobacco containing substantially all of the original water soluble components thereof except for the nicotine.

17. A process according to claim 16 in which the adjustment of the pH value in said concentrated denico tinized extract solution is achieved by cycling said concentrated ,de-nicotinized solution through a mass of magnesium carbonate until the desired pH value is obtained.

18. A process according to claim 7 in whichfadditional water-soluble ingredients customarilyadded to tobacco are added to said water-tobacco mixture formed 'by mixing said denicotinized extract solution with said extracted tobacco.

19. A process according to claim 7 in which to said water-tobacco mixture formed by mixing said de-nicotinized extract solution withsaid extracted tobacco an additional solution containing substantially nicotine-free water soluble tobacco extracts is added.

20. A process according to claim 19 in which said addition-al de-nicetinized tobaccoextract solution is obtained by extnacting tobacco waste with water and de-nicotinizing the formed aqueous extract by means of an ion exchanger adapted to remove nicotine from the solution.

References Cited in the file of this patent UNITED STATES PATENTS 802,487 Wimmer Oct. 24, 1905 1,196,184 Villiers-Stuart Aug. 29, 1916 1,294,3l0 Sayre et al. Feb. 11, 1919 2,226,389 Riley Dec. 24, 1940 FOREIGN PATENTS 364,464 Great Britain Jan. 7, 1932' OTHER REFERENCES Chemical Process Principles (Part I), by O. A. Hougen and K. M. Watson. Pages 177-180. Published 1943 by John Wiley and Sons, Inc, New York. 

1. A PROCESS FOR EXTRACTING NICOTINE FROM TOBACCO, COMPRISING THE STEPS OF TREATING A PREDETERMINED QUANTITY OF TOBACCO WITH A FIRST AMOUNT OF WATER EQUAL TO BETWEEN EIGHT AND TWELVE TIMES THE WEIGHT OF SAID TOBACCO SO AS TO EXTRACT THE WATER SOLUBLE COMPONENTS OF SAID TOBACCO INCLUDING THE NICOTINE AND METAL IONS, AND FROM AN AQUEOUS EXTRACT SOLUTION THEREOF; SEPARATING A MAJOR PREDETERMINED PORTION OF SAID AQUEOUS EXTRACT SOLUTION FROM SAID TOBACCO; ADDING TO THE THUS REMAINING TOBACCO AN AMOUNT OF WATER EQUAL TO SAID FIRST AMOUNT OF WATER; SEPARATING A PORTION OF THE THUS FORMED AQUEOUS EXTRACT SOLUTION EQUAL TO SAID MAJOR PREDETERMINED PORTION THEREOF; REPEATING SAID TREATING AND SEPARATING STEPS WITH FRESH WATER A PREDETERMINED NUMBER OF TIMES; SUBJECTING SAID SEPARATED EXTRACT SOLUTIONS TO ION EXCHANGE AT A PH NOT HIGHER THAN 7.0 WITH AN ION EXCHANGER ADAPTED TO REMOVE THE NICOTINE FROM SAID EXTRACT SOLUTIONS, THEREBY OBTAINING DE-NICOTINIZED EXTRACT SOLUTION; MIXING SAID DE-NICOTIN- 